5 year old female mini Schnauzer turns nasty

I have a 5 year old female mini Schnauzer and a 5 year old male (neutered) bishon. Over the last 4 months my Schnauzer has turned on my bishon and goes in for the kill, she's never been nasty before, the attacks come out of nowhere and I struggle to get her off him, she's such a lovely girl so no idea where this has come from. Can anyone help?

Comments for 5 year old female mini Schnauzer turns nasty

We are very sorry, but we are not animal behaviourists and without knowing all of the facts, are unable to offer any advice. Unless your female is unwell, something has triggered her aggression: Food? Jealousy? Change in the household? Can you think of any changes which happened 4 months ago which may have caused a change in behaviour?
If she continues, we would take her to the vet or a behaviourist before her aggression becomes ingrained. Good Luck.